APPARATUS AND METHOD TO PROCESS ULTRASONIC SIGNAL USING POST-DECIMATION PULSE COMPRESSION

Prior to of the present invention in the embodiment described, ultrasonic imaging techniques utilized in the field of coded excitation technique briefly introduced after, when medical in-situ number, pulse compression (pulse compression) in particular performance of a door of the present invention in the embodiment to overcome the limit point generated number points are employed to sequentially number which when technical means to each other.

Figure 1 shows a degree phase modulation (phase modulation) code according to example pulse compression surface and result are disclosed. Transmits a coded excitation scheme is coded ultrasonic signal reflected signal autocorrelation function (autocorrelation) through performing pulse compression method using matching filters and the like. In the case of performing matched filtering non-coded sequence (uncoded sequence) illustrated in fig. 1 as the strength of the signal is sequentially (intensity) axial resolution of substrate. It is big non-coded sequence as well as the strength of the signal in (Barker) code is sequentially improved axial resolution (range sidelobe) but axially side lobe is generated. In Golay (Golay) code (echo) signal echoes received first process twice through each compressing process same via addition substrate. the strength of the signal it is big compared to the Golay code code twice increased axial side lobe can be a stand-alone when completely ideal number. However twice a feature extraction process (frame rate) present within the reception of frame rate is lowered.

The, depending on the type of code adapted for use with a coded excitation technique can occur while the pulse compression can be selectively transmits an update initialization strategic ultrasonic signal processing strategies to 10sup16. To this end, its implementation of the present invention in the embodiment are code compression process for performing reference position modulation (demodulation) and decimation (decimation) lowers the data rate while reducing hardware complexity by performed after, post - beamforming (post-a beamforming) position shown in tab of the compression performance levels of the same performance as that intended.

Hereinafter with reference to the drawing of the present invention in the embodiment for illustrating the are specifically as follows. Drawing on a designated region of same member presenting a configuration identical to the number.

Figure 2 shows a post - one of the present invention also utilizing signal processing method in the embodiment according to decimation (post-a decimation) pulse compression flow as shown, coded excitation technique can be set easily the position of decimation performing pulse compression processing after quitting.

S210 step, ultrasonic signal processing device is, coded excitation (coded excitation) modulated ultrasonic signal and then through a subject receives a reflected ultrasonic signal.

S220 step, said ultrasonic signal processing device is, S210 is received from a channel via a plurality of beamforming by performing said time delay for ultrasonic signal through (beamforming) produce a focused ultrasound signal.

S230 step, said ultrasonic signal processing device is, focused ultrasound signal quadrature demodulation operation done after step S220 beamforming (quadrature demodulation). The molten, beamforming in-phase signal and quadrature phase component to remove (in a non-phase) output (quadrature) component to be coated.

On the other hand, remove quadrature demodulation step S230 lamppost (low pass filter, LPF) anti - aliasing signal through (anti-a aliasing) can further include the step of processing.

S240 in, said ultrasonic signal processing device is, step S230 remove quadrature demodulation signal sample reduced amount of data (or a data rate reduction of big) the decimation (decimation) performs.

S250 step, said ultrasonic signal processing device is, performing decimation step S240 remove signal center decimation ratio compression set sampling frequency pulse according to a client product of a plurality of hierarchies. The, said center frequency of said ultrasonic pulse and pulse compression for sampling frequencies when product of an integer multiple of the decimation ratio, not when a client terminal not to induce axial side lobe (range sidelobe) number of pulse compression and relatively increasing size of hexalobal billion envelope (mainlobe) effect. In particular, the data rate (data rate) ultrasonic is always a beamforming process immediately after said decimation ratio is inversely proportional to the decreased value. , the process performing the pulse compression, beamforming for matched filter tap (tap) immediately after the ultrasonic pulse compression is always to be coated can be relatively reduced.

On the other hand, remove signal DC rejection (direct current rejection) step S220 beamforming can be performed further comprises. The, performing pulse compression step S250, beamforming remove DC signal is multiplied by each autocorrelation function (auto-a correlation) [ceyk with quadrature demodulation signal using a matched filter preferably processed through the interface.

In addition, pulse compression step S250 remove signal envelope detection (envelope detection) to remove signal scan conversion (scan conversion) performing envelope detection further comprises performing disapproval.

Figure 3 shows a coded excitation ultrasound imaging using also pulse compression can be performed in various locations (A, B, C position) plane as the illustrated a, horizontal grill compares the respective positions, of the present invention in the embodiment are finally 'C' positions by techniques described characteristics can be exhibited in 2000.

'A' position a position pre - beamforming (pre-a beamforming), ultrasonic signal received at each RF data channel circuit checking (310) previously performing pulse compression upper face of the compression properties. However plurality of channels for each pulse compression thus has high complexity should be performed any restrictions.

'B' position a position post - beamforming (post-a beamforming), circuit checking (310) after performing pulse compression to be coated. The, 'A' pre - having an upper position of the same compression performance in order to accurate beamforming circuit checking are required. The position of the pre - to the end of post - beamforming while single compression filter than a filter in the case of bit clock is divided beamforming Reduces the times.

'C' position a position post - decimation (post-a decimation), DC rejection (direct current rejection) (320), quadrature demodulation (quadrature demodulation) (330), a lamppost (low pass filter, LPF) (340) to decimation (350) after pulse compression performance of the lungs. The decimation after performing pulse compression when, twice the number of filter 'B' compared although a relatively low data rate (data rate) obviating decimation but performed by performing filtering in advantage can be. In particular, 'C' position (tap) due to low data rate in the case of reducing the number of tap filter can be, for pulse compression and after process including smart phone can be a separate system making it possible to perform hereinafter. Only, 'C' pulse compression in execution, demodulation (demodulation) (330) and decimation (decimation) (350) in transit data pulse compression distortion of coated on surfaces of the post such that the reflected compression performance compared - beamforming a drawback.

Also as described through prior 2, of the present invention in the embodiment are ' C'according to position because the post - decimation of two, or more of the inspection can be pointed to the headend by exposing the lower face of the technical means takes only broadcast receiver.

In the Golay code for facilitating descriptions hereinafter 4 cycle (4 cycle golay code) is using each in the embodiment described, the Golay code selecting inner A, each B code and Using the air. The present invention is more specifically described in the embodiment these a manner that, in the embodiment of the present invention non-negative number corresponding to one range are disclosed therein.

First transmits defect/deficiency defined waveform. Selected Golay A, next equations defined such as Golay B code 1. In this case L and length of codes selected means, the length of the period in the embodiment 4 is N and corresponding sample (sample) of number disclosed.

The central processing unit selects a pulse waveform of the Golay code and the quality of the above mathematical type 2 transmit pulses such as convolution (convolution) operation , When the generating, Golay code also 4 was generated using the waveform of the pulses transmitted through example.

The number, post - beamforming and post - decimation in each position pulse compression case method performing operations on the process block degree for each result compressed sequentially (1), (2) and (3) of been that deforms to process.

(1) Post -Beamforming Position pulse compression deformation also block

Figure 5 shows a pulse compression process (post-a beamforming) position also post - beamforming to drawing to explain the, such as in (a) of Figure 5 generally post - beamforming Golay code pulse compression position (510) 5 (b) of electron exchange [...] along a DC rejection filter such as (DC rejection filter, DCR) (520) can be modifying behind.

Specifically herein, expressions 2 transmit pulses After transmitting, through each channel after receiving the reflected ultrasonic signal transducer received ultrasonic signals of each channel beam focusing Defined as follows. Wherein [...] using filtering operation (distributive law) in exchange for distribution of laws such as next equations can be modified according to the law (Commutative law) 3.

3 (B) of Figure 5 as the expressions the finally block also can be modified.

(2) Post -Decimation Position pulse compression deformation also block

Figure 6 shows a pulse compression process also post - decimation (post-a decimation) position as drawing to explain the, shown in (a) of Figure 6 post - decimation position pulse compression block (610) next equations such as 4 position of a lamppost (Low pass filter, LPF) (620) to decimation (630) front can be changing.

Is a mathematical equation 4 Precursor to The same also established as follows. Each matched filter expressions 4 of Figure 6 (b) according to the position of compression filter code using exchange laws to change such as , (Nth M) sampling (up-a sampling) by a decimation magnification M - up to and Precursor decimation magnification M=2 to 7 was also through each code compression filter when the waveform of the example. Wherein, sampling frequencies center decimation ratio when multiplied by a second integer multiple of each other, and , And and Coincidence is as follows. In addition, (c) assessing the result of Figure 6 coupled together on a tension through code compression (610 + 630→615) after a lamppost (620) to perform the disapproval.

(3) Compression filter position according to final performance for comparison Expression of the block Identifying difference

Figure 8 shows a also said (1) according to a result of said beamforming position post - (2) according to a result of drawing to compare performance of post - decimation position as pulse compression, outputted from each block in (a) of Figure 8 and , And and Comparing the value of such as disclosed. Using the same two structure according to compression result is also used for broadcast receiver having two pulse compression this difference derived in a specific example.

In post - beamforming unit is then generating electron distribution of pulse compression along such as 5 equations can exhibit.

In addition, pulse compression post - decimation position unit is sampling frequencies center decimation ratio when multiplied by a second integer multiple of each other, and , And and 6 Equations can exhibit such as same to the record.

The, multiplication and not post - pulse compression and post - beamforming position established [...] exchange certain pulse compression is the result thereof is alike decimation position. I.e., (b) of Figure 8 in the two blocks do not have also includes an element for pulse compression performance. The two blocks of Figure 8 (a) degree of the post - beamforming position and post - pulse compression means of broadcast receiver according to code compression performance comparison decimation position.

(4) Post -Beamforming Pulse compression position

Post - - sine and cosine for performing demodulation by multiplying a pulse compression beamforming position of Figure 8 (a) represents the left button equations 7 and also block such as pulse compression such as disclosed.

In expressions 7, which means the length of a code used for the L, L=4 here are disclosed. N corresponding sample (sample) is longer period of number disclosed. Via a process on the result can be the result (n) and c (=8) panels have identical configurations can be an article making sure that the 2L amplitude.

The number of an ultrasound signal demodulation cosine pulse compression, multiplied - sine 8 the following equations such as disclosed.

The left block of Figure 8 (a) obtained in the step (n) to the result of the face c cosine, multiplied by form - sine is under or over.

(5) Post -Decimation Pulse compression position

(A) post - decimation position pulse compression process precursor degree right block of Figure 8, 9 next equations such as disclosed.

As a result post - decimation position pulse compression is and - Sine and cosine signal multiplied by the adjustment filter ring by adding to each pulse compression by as much disclosed.

The, multiplied by the cosine of Figure 9 (a) and shown pulse such as sampling frequency ( ) Is ultrasonic pulse center frequency ( ) On the decimation ratio ( ) Multiplied by a second integer multiple of each other gives not divided sometimes can be fixed. is When bail integer, i.e. (A) the upper part of the picture of Figure 9 such as 2 π phase such as after the last phase of the excitation signal by repeatedly up the substrate. (A) such as the underside of the picture of Figure 9 however 2 Π phase when the phase of the cross product is by repetitive after a different next period without signal appears substrate. This - sine pulse also similarly received signals.

If it home without distortion of the signal in the first process, the receiving signal of the Golay code each performing DC rejection filter , L=4 of Figure 9 (b) and since, such as in (c) the To, the Pivotably represented. (B) of Figure 9 to the signal of interest, such as cosine (c) product , 2042 Obtain a signal. The, When the pulse signals are transmitted to a rotated form of Figure 9 (b) required whose cosine phase, (c) a pulse such as cosine pulse period and outputs the lOc cos0, cos1, cos2, pivotably cos3 represented.

the result the , X1, X2, to - X3, The X0, X1, - X2, X3 can be represented, a procedure is shown in (a) of Figure 10 left deleted.

(B) of Figure 10 in same process result of combining results were straight left adjustment filter ring of Figure 10 (c) and precursor pulse compression can be left as it is representing. The, X2, X1 and X3 is not 2X0-2X2 2X1-2X3 0 X0 and such is not on. I.e., axial side lobe number is not volatile. Performing pulse compression in the post - beamforming the product and cosine pulse obtained by multiplying a cosine pulse in a pulse compression result of performing decimation - after post-flow prevention. This - sine pulse Q it is even the same even data received signals.

While (A) whose cosine pulse is repeated when the cosine pulse such as such as values of Figure 10 in right cos0, cos0, cos0, pivotably cos0 represented. Having performed DC rejection filter received signals can likewise Golay code the To, the Pivotably represented. The and A result obtained by multiplying each cos pulse The X0, X0, X0, to - X0, The X0, X0, - X0, X0 of Figure 10 (a) can be represented in a process such as shown in right deleted.

(B) of Figure 10 in tension as a result of Figure 10 (c) is straight adjustment filter ring precursor process same result of pulse compression are disclosed. The, Unlike the case of The wetting ability of under the axial side lobe number encoded. The Performing pulse compression in post - beamforming in the product and cosine pulse obtained by multiplying a cosine pulse after performing post - decimation position and another result pulse compression are the same. I.e., When the decimation position pulse compression and post - pulse compression performance of post - beamforming position are the same.

In post - beamforming and post - decimation and For applying pulse compression when performing envelope detection (envelope detection) in fig. 11 having performed result such as disclosed. The reference also 11, Side lobe (range sidelobe) appearing when post - decimation position pulses in axial compression and the size making sure that the envelope of a hexalobal (mainlobe) can be. While As post - decimation position when post - beamforming position pulse compression coincide substrate.

Figure 12 shows a post - one of the present invention also utilizing signal processing device in the embodiment according to decimation (post-a decimation) pulse compression (10) are independent each other and block shown, 2 each ultrasonic signal processing method is implemented through the hardware of a currently discussed view of him. The, descriptions here to avoid redundancy of outline my diffuse to the respective components.

A receiving part (12) is, modulation section (11) coded excitation (coded excitation) from a subject through modulated ultrasonic signal and then the means for receiving the reflected ultrasonic signal are disclosed.

Beam bunching department (13) includes, receiving part (12) through a time delay for ultrasonic signal received via said beamforming (beamforming) performs.

Demodulation unit (14) is, remove a beamforming signal quadrature demodulation (quadrature demodulation) a plurality of hierarchies. The demodulation unit (14) is, beamforming remove signal (in a-phase) in-phase and quadrature phase component (quadrature) component separately outputting a compared with, anti - aliasing (anti-a aliasing) orthogonal demodulated ultrasonic signal that performs (not shown) can be further comprises a lamppost (low pass filter, LPF).

Decimation [...] (15) is, quadrature demodulation signal to reduce the amount of data the decimation factor (decimation) remove a sample performs.

Pulse compression section (16) is, decimation performed to a client product of remove signal center decimation ratio set sampling frequency pulse according compression has a plurality of hierarchies. The, said center frequency of said ultrasonic pulse and pulse compression for sampling frequencies when product of an integer multiple of the decimation ratio, not when a client terminal not to induce axial side lobe (range sidelobe) number of pulse compression billion (mainlobe) is equal to a relative increase in the size of the envelope and a hexalobal. In particular, said pulse compression section (16) is, beamforming data rate (data rate) is inversely proportional to said decimation ratio immediately after ultrasonic is always a decreased value. The, said pulse compression section (16) is, immediately after the ultrasonic pulse compression is always a beamforming for matched filter tap (tap) number having a value relatively to the suction to the edifice.

On the other hand, DC (direct current rejection) beamforming signal (not shown) performing [ceyk father remove DC rejection can be further comprises, thereby said pulse compression section (16) is, beamforming remove signal multiplied signals are DC [ceyk with quadrature demodulation using matched filter each autocorrelation function (auto-a correlation) preferably through pulse compression.

In addition, ultrasonic treatment device of Figure 12 (10) is, remove signal pulse compression detection section (not shown) performing envelope detection (envelope detection) envelope to remove signal envelope detection (not shown) performing scan conversion unit further comprises encrypted (scan conversion) disapproval.

Of the present invention in the embodiment according to the, coded excitation technique according to post - pulse compression process performing pulse compression in selected position while post - beamforming decimation obviating the same compression performance ultrasonic signal processing techniques to overlook number was. In addition, pulse compression process by performing pulse compression in low data rate through smart phone post may be output as well as for separate system including hereinafter, matched filter tap number (tap) by reducing the complexity of the hardware is used as the flange.

The present invention various in the embodiment above the tank by the transformed for flaws. The present invention in the art of the present invention belonging to the present invention is inputted from deviating from a person with skill in the art is essentially embodied in the form of properties may be modified may be understand are disclosed. The definitive aspect as well as the descriptive disclosure in the embodiment are contemplated aspect should. The aforementioned range of the present invention description and claim rather than as shown, and the present invention is in a range equal to all differences may be carried on an will be interpreted.